Magnetic float point sensor for high pressure containers

ABSTRACT

A float switch for operating a magnetic switch utilizing an oilfilled chamber in which there is supported for limited movement a magnetic member for energizing for a given position of the magnet a reed switch assembly mounted on the exterior of the chamber. A float member exterior of the housing and connected to the magnet by means of a bellows seal arrangement positions the magnet within the interior of the housing in accordance with the change of liquid level acting upon the float.

United States Patent 1 1 ,7 ,9

Akeley [451 Nov. 14, 1972 1541 MAGNETIC FLOAT POINT sENsoR 2,204,1616/1940 Shepherd ..200/84 c FOR HIGH PRESSURE CONTAINERS 2,116,415 5/1938Shenton ..200/84 R 3 022 397 2/1962 066111161 ..200/84 c 72 1 1 Ll dT. 1i Akeley calf 2,587,747 3/1952 McCullough ..200/84 B [73] Assignee:Simmonds Precision Products, Inc., 3,588,404 6/1971 Akeley ..200/84CTarrytown. NY. 2,646,067 7/1953 Smith ..200/84 R [22] Filed: March 24,1971 Primary ExaminerDavid Smith, Jr. [21] Appl. No.: 127,810

Attorney-Edwin E. Greigg Related US. Application Data [57] ABSTRACT [63]g gsg gg g 8 April A float switch for operating a magnetic switchutilizing e an oil-filled chamber in which there is supported forlimited movement a magnetic member for energizing [52] US. Cl. ..200/84R, 200/84 B, 200/84 C 51 Int. Cl. ..H01h 35/18 a the magnet a reed assembly mounted on the exterior of the chamber. A [58] Field ofSearchMmO/sd' 84 84 4 3 float member exterior of the housing andconnected to the magnet by means of a bellows seal arrangement positionsthe magnet within the interior of the housing [56] References Cited inaccordance with the change of liquid level acting UNITED STATES PATENTSp the float- 3,l68,625 2/1965 Hill ..200/84 C 6 Claims, 2 DrawingFigures 4 2' 8 S 5 J \l/ 2 30 Q Q I l2 2L MAGNETIC FLOAT POINT SENSORFOR HIGH PRESSURE CONTAINERS This application is a continuation of Ser.No.

815,146, filed Apr. 10, 1969 now abandoned This invention relates tolevel sensing control switches, and more particularly to afloat-actuated switch for use with a liquid container under relativelyhigh pressure wherein installation is effected by means of a simple pipethread mounting.

Where it is desirable to employ float-actuated switches in liquidcontainers, it is often the case that several such switches be employedfor controlling exterior equipment responsive to different levels of theliquid within the container. As a consequence, it often becomesnecessary to install such float switches within the container after thesame has been constructed in response to new demands created by thesystem within which the container is used. For this purpose, it isdesirable to install such switches externally of the container after thesame has been installed and in operating condition and in many casesoperating under high pressure conditions. Further, it is desirable thatsuch switches be small in size, simple in construction and economical tomanufacture, such that they can be replaced as a complete unit ifnecessary. Accordingly, the purposeof this invention is to provide sucha switch which is easily installed and which can utilize a practicaldesign for achieving high pressure capability as well as reliableoperation.

It is an object of this invention to provide a float switch point sensorutilizing a float cooperating with a magnetic member within anoil-filled chamber for energizing a magnetic reed switch assemblymounted on the chamber.

It is another object of this invention to provide a float switch pointsensor utilizing a float in cooperation with a mercury switch containedwithin an oil-filled chamber.

It is a further object of this invention to provide a point sensor floatswitch for use with a liquid container which can be easily installedthrough a simple pipe thread mounting.

It is yet another object of this invention to provide a dirt-resistant,high pressure point sensor for use in a liquid container which utilizesa float member in cooperation with a magnetic member contained withinthe chamber for actuating one or more adjustably mounted reed switches.

According to one aspect of this invention there is provided a hollowchamber closed at one end and having a pipe thread mounting at its otherend for engaging a suitable aperture provided on the side wall of aliquid container. The chamber is oil-filled and is provided with abellows seal member at its open end for supporting a rod having a floatat one end exterior of the chamber and a magnetic member at the otherend which is interior of the chamber. The bellows acts as a seal andpivotal diaphragm support at a point of balance on the rod member. Areed switch is positioned by means of an adjustable mount on theexterior face of the chamber such that the reed switch becomes activatedby the magnetic field from the magnet when the latter positions itselfat the bottom of the chamber. The reed switch can be rotatably adjustedto any position on the exterior surface of the chamber after the pointsensor is installed.

Other objects and advantages will become apparent from a study of thefollowing specification and drawings, in which:

FIG. 1 is a side elevational view in section of the float switchconstructed according to the principles of this invention; and

FIG. 2 is a side elevational view in section of a modified float switchassembly in accordance with the principles of this invention.

Referring now to FIG. 1, there is shown a hollow chamber 2 which isfilled with oil or other suitable viscous fluid having dielectriccharacteristics through a suitable fill plug 4. The chamber 2 has athreaded open end mounting 8 in which there is fitted a bellows sealdiaphragm member 10. This member supports a rod 12 at its center ofbalance and that portion of the rod 12 which extends within the interiorof the housing 2 is fitted with at least one cylindrical magnet member14, although two are shown in the drawing. The other end of the rod 12supports a hollow float member 16. The rod 12 has a portion thereofexterior of the chamber 2 provided with threads for adjustablysupporting a counterweight member 13 for achieving a desired balancedcondition between the magnets 14 and the float member 16. The closed endof the chamber 2 is provided with an extending screw thread member 18which receives an apertured bracket member 20 which, in turn, supports aconventional magnetic reed switch assembly 22 on the exterior face ofthe chamber 2. It will be understood, of course, that the reed switch 22becomes activated when under the influence of the magnetic fieldemanating from the magnets 14. This phenomenon occurs when the magnets14 approach the vicinity of the switch 22 at the bottom of the chamber2. As shown in FIG. 1, the magnetic reed switch assembly 22 can berotated to any position on the exterior surface of the chamber 2 bymerely rotating the bracket member 20 about the threaded stud 18. Asuitable nut is secured to the stud 18 to clamp the bracket 20 in adesired given position.

The entireassembly may be screw-threaded into a drilled aperture in thewall of a suitable liquid container at any height by means of the pipethreaded fitting 8. After the chamber 2 has been secured to the wall ofa liquid container, the reed switch assembly 22 may then be adjusted tooccupy a position directly under the magnets 14 at the bottom of thehousing 2, as shown in FIG. 1.

The magnets 14 are radially magnetized so that they influence the reedswitch independent of the reed switch rotational position on theexterior surface of the chamber 2. As mentioned earlier, the switchposition is adjustable so that it can be rotated to a desired top orbottom position, or for that matter, a number of switches can beemployed in different circumferential positions, for example, twoswitches can be provided, one on the top and one on the bottom, afterthe pipe thread mounting has been completed. Because of the oil fillwithin the chamber 2, dirt or other particles that might be in theliquid operating the'float 16 can be kept away from the magnets 14 aswell as the electrical reed switch assembly 22. Also, the presence offluid within the chamber 2 increases the pressure capability of thesensor itself by virtually removing any pressure drop across the pivotseal bellows member 10. This feature is an important one when the pointsensor, according to this invention, is utilized under high pressureconditions. Also, the point sensor according to FIG. I will operate as atop mounted device as well as a side mounted device. For a top mounting,however, the arm 12 must be bent to approximately 90 at a point which isexterior to the chamber 2. In this arrangement the counterweight 13 maybe dispensed with if so desired, wherein the weight of the float 16 willbias the magnets 14 against that part of the chamber 2 which is not inthe vicinity of the reed switch assembly 22. When a change in liquidlevel causes the float to move, however, in this case in a clockwisedirection about the seal 10, the magnets 14 will swing to the oppositeinterior wall of the chamber 2 in the vicinity of the reed switchassembly 22.

In operation, then, the float 16 will energize the reed switch assemblywhenever the float is raised by a change in liquid level causing the rod12 to pivot about the seal and and pivot diaphragm bellows in aclockwise vdirection and thereby position the magnets 14 at the bottomof the chamber 2. with the magnets 14 in this position, the reed switch22 will become energized under the influence of the magnetic fieldemanating from the magnets 14 in the known manner.

In FIG. 2 there is shown another embodiment of the point sensoraccording to this invention. When like elements between the FIG. 1embodiment and FIG. 2 embodiment are described, the same referencenumerals will be used but in this case they will be primed. As shown, achamber 2 is tilled with oil by means of the oil plug 4'. The chamber 2has a threaded mount 8' at its open end and provided within the open endis the seal and pivotal diaphragm bellows member 10' which supports arod 12', one end of which is exterior of the chamber 2 and supports thefloat member 16'. The portion of the rod 12' within the interior of thechamber 2' is provided with a counterweight 24 having an axiallyoriented notch 26 which receives the free end of a flexure strip member28, the other end of the flexure member being embedded in the face plateor end wall 30 of the chamber 2. Mounted on the flexure strip member 28is a conventional mercury switch element 32 having appropriateelectrical leads extending therefrom through the end plate 30. The freeend of the flexure member 28 and the notch 26 of the counterweight 24,in effect, form a universal joint such that the rod 12' can pivot in anydirection about the pivot diaphragm seal 10 in order to impart movementto the flexure member 28 and hence cause the mercury globule to moveeither vforward or rearward for bridging the gap between the appropriatecontacts in one of two positions.

The operation of the point sensor embodied in FIG. 2 is similar to thatdescribed with the embodiment shown in FIG. 1. It will be understood,however, that with a mercury switch the point sensor can only be used ina horizontal position unlike the point sensor described in FIG. 1. Themercury switch may be replaced after the point sensor is installed, andfor this purpose the end face 30 is removed by unfastening suitablescrews around the periphery of the plate 30. When the switch is replacedin this manner, however, the interior of the chamber 2' must bereplenished with a new supply of oil. The end plate 30, of course, canbe rotated after assembly inorder to properly orient the magnetic switch32 with respect to the housing 2'. Such rotation will be limited,however, by the number of symmetrical mounting screws provided.

It will be seen that the point sensor switching assemblies according tothe concepts of this invention can be readily installed exteriorly of aliquid container by merely screwing the assembly into an apertureprovided on the container. Also, it will be seen that the switchassembly can be constructed to extremely small dimensions allowing fordesired savings'in space and cost. The point sensor switching assemblyaccording to this invention can be used in oil, water or other liquidstorage tanks under high pressure to indicate high and low levels or tocontrol the action of pumps used for filling or emptying a tank.

That which is claimed is:

1. A float switch assembly for a high pressure liquid containercomprising a hollow chamber having an end wall and open to atmosphere atthe other end and arranged to contain a dielectric fluid and furtherincluding a thick-walled, tough, flexible bellows seal member locatedinteriorally thereof adjacent to said other end, a rod member extendingthrough said seal member and supported thereby and having at one endthereof exterior to said housing a float member and at the other endthereof extending within the interior of said housing a magnetic member,said rod extending through said housing axially thereof when said floatmember is positioned above the liquid level of said high pressurecontainer, weights adjustably mounted on said rod member to aid inbalancing the same, and a magnetic reed switch responsive to saidmagnetic member and carried by a bracket secured to the exterior of saidhousing, said bracket being rotatable through an arc of 360 about thechamber so that it can be correlated into any position relative to themagnetic member.

2. A float switch assembly for a high pressure liquid containercomprising a hollow chamber having an end wall and open to atmosphere atthe other end and arranged to contain a dielectric fluid and furtherincluding a thick-walled, tough, flexible bellows seal locatedinteriorally thereof adjacent to said open end, a stub rod memberextending through said flexible seal member and supported thereby andincluding at the end exterior and adjacent to said housing a floatmember and on the other end extending within the interior of saidhousing a counterweight including a coupling means, said rod extendingthrough said housing when said float member is positioned above theliquid level of said high pressure container, said counterweightadjustably mounted in coaxially adjustable position on said rod memberto aid in balancing the same, a flexure member pivotally recessedbetween one end of the counterweight coupling means and said end wall ofthe chamber and mercury switch means carried by said flexure member.

3. A float switch assembly according to claim 1, in which the weight isaxially adjustable relative to said rod member.

4. A float switch assembly as claimed in claim 2, wherein the mercuryswitch means include electrical leads extending through the end wall ofthe chamber.

5. A float switch assembly for a high pressure liquid containercomprising a hollow chamber closed at an end by a flexible seal memberand arranged to contain a dielectric fluid, a rod member extendingthrough said seal member and supported thereby and having at one endthereof exterior to said housing a float member and at the other endthereof extending within the interior of said housing a magnetic member,a weight adjustably mounted on said rod member to aid in balancing thesame, and a switch responsive to said magnetic member located exteriorlyof said housing and carried by a bracket secured to the exterior of saidhousing, said bracket being adjustable circumferentially of said housmg.

6. A float switch assembly for a high pressure liquid containercomprising a hollow chamber closed at an end by a flexible seal memberand arranged to contain a dielectric fluid, a rod member extendingthrough said flexible seal member and supported thereby and having atone end exterior to said housing a float member and on the other endextending within the interior of said housing a counterweight includinga coupling means, a

flexure member pivotally recessed between one end of the counterweightcoupling means and said end wall of the chamber and mercury switch meanscarried by said flexure member.

1. A float switch assembly for a high pressure liquid containercomprising a hollow chamber having an end wall and open to atmosphere atthe other end and arranged to contain a dielectric fluid and furtherincluding a thick-walled, tough, flexible bellows seal member locatedinteriorally thereof adjacent to said other end, a rod member extendingthrough said seal member and supported thereby and having at one endthereof exterior to said housing a float member and at the other endthereof extending within the interior of said housing a magnetic member,said rod extending through said housing axially thereof when said floatmember is positioned above the liquid level of said high pressurecontainer, weights adjustably mounted on said rod member to aid inbalancing the same, and a magnetic reed switch responsive to saidmagnetic member and carried by a bracket secured to the exterior of saidhousing, said bracket being rotatable through an arc of 360* about thechamber so that it can be correlated into any position relative to themagnetic member.
 2. A float switch assembly for a high pressure liquidcontainer comprising a hollow chamber having an end wall and open toatmosphere at the other end and arranged to contain a dielectric fluidand further including a thick-walled, tough, flexible bellows seallocated interiorally thereof adjacent to said open end, a stub rodmember extending through said flexible seal member and supported therebyand including at the end exterior and adjacent to said housing a floatmember and on the other end extending within the interior of saidhousing a counterweight including a coupling means, said rod extendingthrough said housing when said float member is positioned above theliquid level of said high pressure container, said counterweightadjustably mounted in coaxially adjustable position on said rod memberto aid in balancing the same, a flexure member pivotally recessedbetween one end of the counterweight coupling means and said end wall ofthe chamber and mercury switch means carried by said flexure member. 3.A float switch assembly according to claim 1, in which the weight isaxially adjustable relative to said rod member.
 4. A float switchassembly as claimed in claim 2, wherein the mercury switch means includeelectrical leads extending through the end wall of the chamber.
 5. Afloat switch assembly for a high pressure liquid container comprising ahollow chamber closed at an end by a flexible seal member and arrangedto contain a dielectric fluid, a rod member extending through said sealmember and supported thereby and having at one end thereof exterior tosaid housing a float member and at the other end thereof extendingwithin the interior of said housing a magnetic member, a weightadjustably mounted on said rod member to aid in balancing the same, anda switch responsive to said magnetic member located exteriorly of saidhousing and carried by a bracket secured to the exterior of saidhousing, said bracket being adjustable circumferentially of saidhousing.
 6. A float switch assembly for a high pressure liquid containercomprising a hollow chamber closed at an end by a flexible seal memberand arranged to contain a dielectric fluid, a rod member extendingthrough said flexible seal member and supported thereby and having atone end exterior to said housing a float member and on the other endextending within the interior of said housing a counterweight includinga coupling means, a flexure member pivotally recessed between one end ofthe counterweight coupling means and said end wall of the chamber andmercury switch means carried by said flexure member.